Core for tubular castings



Oct. 30, 1945. A. E. TROIEL CORE FOR TUBULAR CASTINGS 3 Sheets-Sheet 2 .Filed Sept. 27, 1943 I -Zo INVENTOR;

L 3., m WW 0 R W M v T E A W TY B 76 Z A. E. TROI EL CORE FOR TUBULAR CASTINGS Oct. 30, 1945.

Filed Sept. 27, 1943 3 Sheets-Sheet INVENTOR.

ARTHUR TIQO/ZL 9 Qfiem ATTOQ/VEYS.

Patented Oct. 30, 1945 UNI TED STAT E S PAT EN T F F ICE .ooms FOR TUBULAR CASTINGS Arthur E. Troiel, Berkeley, Calif. Application September 27, 1943, SerialNo. 504,031

2 Claims.

The presentinventionrelates to cores ior'casting tubula shapes in concrete or the like and particularly to a collapsible cylindrical core designed to be easily extracted from a long hollow tubular casting. a

Lon tubular concrete castings are useful as conduitsfor various purposes and'are also used as protective and strengthening casings over wooden piles. Even where wharves are built principally of concrete piles, wood bracing piles driven at a diagonal to the vertical supporting piles are commonly used and'these "wood piles are jacketed with precast concrete tubular members. The present invention is ideal for forming concrete jackets for this purpose, and the invention is illustrated and described herein in such an application, although, as will be apparent fromthe description, it is readily adaptable to use in casting any hollow object, particularly where a cylindrical or similarly shaped core is required.

It is the object of the present invention to provide a lightand durable core for making cylindrical castings having simple means for contracting its dimensions to facilitate its extraction from the casting after the casting materialhas 'set.

A further object is the provision of a cylindrical core member made up of curved metal plates with means for fixing the member at a predetermined diameter, and means for contracting its diameter without causing bulging ,or harmful distortion of the plates of which it is made.

Further objects and advantages of the invention are made apparentin the following specifications wherein detailed reference is made to the accompanying drawings.

In the drawings:

'Fig. l is a transverse section through a core constructed in accordance with the present invention illustrating the core in its fully expanded position;

Fig. 2 is a similar view showing thecore con- .tracted and illustrating the same disposed within a section of a pile jacket which has been-cast around it before itwas constructed;

Fig. 3 is a longitudinal section taken on line III- II of Fig. 1;

Fig. 4 is an enlarged longitudinal sectional view of the jack screw nut illustrated in Fig. .3;

Fig. 5 is a similar view of a set of the pivotal fittings illustrated in Fig. 3;

Fig. 6 is a fragmentary perspective view of some of the plates which make up the body of the core illustrating-a meansfor connectingabutting ends of the plates;'and

Fig. '7 is a perspective view of a'porti'on "of a cover plate'illustrating a joint-between the-abutting ends.

As illustrated in'Fig. 1, the cylindrical core of the pre-sent invention is-madeupo'f three substantially identical -'arcuate sections l9, H and I2, and a fourth similarly shaped section -13. Each of the sections 10, ll and 12 are provided with flanged edges I4 which-project radially in- Wardly pfthe cylinder and these flanges maybe joined'to the flanges of adjacent sections "and preferably also to reenforcing angular members shown at t5, the joiningbeing accomplished either by bolts or rivets,not shown, or bywelding. The plates 10 or 12 are off-set as'indicated at I6 for reception ofthe edges of the plate 13 hereinafter referred to as a cover plate. One edge of theplate I3 is secured as by bolts I! to the section 12, and the other edge overlaps the section It], both edges being received'by the offset portions of the sections l0 and 12 in order that the outer periphery of the core'will present .a smooth cylindrical surface. In order to cause the plate l3 to lie snugly in position,'it ispreferably curved ona slightly smaller radius thanthe plates 10, H and [2. For example, if the core is 16 inches in diameter, the plates l0, .H and I 2 are curved on an 8 inch radius, while the plate I3 is given an original curve or are on a 7 inch radius with the result that with its one edge securely fastened as by the bolts 11, its other edge will lie snugly in the recess of the plate It and .it will assume an .arc of substantially the same radius as'the other three sections.

At the points of juncture of the four sections .ID to l3 are sets of links l8 which, as illustrated in Fig. 3, are connected with fittings H! which are mounted for rotation relative to a shaft '29 which is disposed axially of the core. Each of the fittings l9 consists of an annular portion which embraces the shaft 20 (see'Figs. 3, 4 and 5) and a lug -21 to which the inner ends of one of the sets of links l8'is pivoted, the outer ends of the'links'being pivoted, as'shown, to the flanges M. 'The fittings l9 are arranged in spaced groups of 'four, each group being retained against longitudinal movement with relation to the shaft at opposite ends of the group. Of the four fittings IS in each group the'lugs 2| on .the endmost fittingslare elongated as shown so that their points of pivotal-connection with the rings l8 will be in the same plane as the corresponding pivotal points onthe shorter lugs of the intermediate pair ofifittings l9; consequently, :each of the groups of links l8 consists of four sets of links radiating from a central shaft in a common plane, with each set free to rotate relative to the shaft and relative to the other sets.

The shaft may be moved longitudinally with relation to the main body of the coreby means of a jack screw 23 (see Fig. 3) which has a square end 24 for the application of a suitable wrench and it operates through a nut 25 (see Fig. 4) which is braced by links 26 connected at their outer ends to the nut and at their inner ends to the flanges M, as shown in Fig. 3. The connections of the links 26 to the nutare made through ltgs 21 on collars 28, which collars embrace the nut 25. The

collars are free to rotate on the nut, but are re.

tained against longitudinal displacement by a flange 29 on one end of the nut and a screwed collar 30 at its opposite end. A set screw 3| preferably locks this collar in place. The jack screw 23 is connected to the end of the shaft 29 through the medium of a ball bearing swivel joint as shown at 32, so that upon turning of the screw the shaft 7 20 is moved longitudinally without being rotated.

Such longitudinal movement of the shaft 20 relative to the body of the core draws the links [8 to an angular position effectively shortening the length of the links so that the body of the core formed on the plates II] to l3 inclusive is drawn inwardly. Were allof these plates rigidly connected, inward movement of their joined edges would effect a bulging or a swelling intermediate their edges with the. result that the tube would be enlarged in its diameter unless it were contracted to a point beyond the practical limits of the flexibility of the metal of which it is constructed. However, by virtue of the fact that the cover section I3 is free atone of its edges, and the fact that the links l8 are connected to the central shaft 23 through the medium of the fittings l9, each of which-swivels independently on the shaft, this contracting action causes the core to assume the shape illustrated in Fig. 2 wherein all of the sections ID to l3, though retainin substantially their normal curvature, are positioned to reduce materially the outside diameter of the core. This result is obtained by reason of the fact that thesections 10, II and 12 are free to contract slightly as a unit the links l8 which join them to the central shaft pivoting. about the shaft to accommodate this action. The free edge of the cover section I3 assumes a position overlapping a relatively large area'of the section J0. In this manner a materially reduced outside diameter is effected without imposing unusual or distorting strain on any of the parts of which the tubular shape is formed. 'As the links 26 which brace the jack screw nut against the core are pivotally connected to the nut, they also are free to assume the positions of the links shown in Fig. 2 upon contraction of the core. 7

In using the core, the 'jack screw 23 ist-urned to bring the parts to the position illustrated in Figs. 1 and 3. The core is then placed between outside form walls of any conventional construction for the formation of the concrete shape illustrated in Fig. 2, or whatever other shape maybe desired, and-conventional reenforcing material may ,be fixed between the core and the outer forms, if desired. The concrete is then poured and after it has set, the jack screw 23 is manipulated to move the shaft 20 longitudinally and through the links I8 draw the walls of the core to the positions illustrated inFig. 2. Inthiscondition the core may easily be extracted from the casting without damage to either, and may quickly be set up for further use.

The description thus far assumes the plates [0 to 13 which constitute the body of the core to be made each of a single piece of metal. This would be impractical in very long cores and would be undesirable because it would definitely fix the length of each core. The invention contemplates the use of short plates joined in such a manner that the cores may be made up in various lengths and may be disassembled for convenience in transportation and storing.

A preferred means for connecting short pieces to form the plates in, H and I2 is illustrated in. Fig. Gwherein abutting ends of pieces which orm the plate H are shown as connected by a short piece 35 curved to conform to the inner surface of the ,plate i l and preferably stiffened along itslongitudinal edges by angle members 36 either welded to or formed integrally with the piece 35.

The piece 35 is secured to the separate portions of the plate II by welding or rivets 31 at one end and removably secured at the opposite end as by bolts 38. Through this construction the plates I0, I I and I2 may be made up in any desired lengthr and the rigidity of the whole tubular structure is maintained by staggering the joints so madeat the abutting ends of the short pieces.

The cover plate I3 may be made of short pieces connected as shown in Fig. 7 by a slip joint formed of a curved member 39 secured to one of the pieces and a curved and ofiset member 40 secured to the other. Both of these members are provided with slots 4| along which they are welded in place. When the ends of the pieces forming the plate I3 are brought into abutment, the member 39 slips under the offset portion of the member 40 to form an interlocking but readily detachable connection.

The central shaft 20 may also be made of separable sections joined, as illustrated in Fig. 5 by a coupling 43 threaded and welded as at 44 to one of the sections and threaded to the other section to permit its removal. the position and performs the function of one of the collars 22 shown in Fig. 3,.

The invention is herein described in a specific form for purposes of illustration but is not limited by this disclosure as it is adaptable to various changes in construction and detail, all within the scope of the appended claims.

Having thus described my invention, .what I claim and desire to secure by letters patent is:.

1. A contractible tubular core comprising an outer cylindrical shell, a shaft disposed axially thereof and sets of radial links connecting said shaft and shell, each set of links being connected with said shaft through fittings mounted to swivel on the shaft, said fittings being longitudinally distributed on the shaft but having pivotal connections with the links in a common plane atv right angles to the shaft. l

.2. A contractible tubular. core comprising an outer cylindrical longitudinally extended shell, a shaft disposed axially thereof throughout the entire lengthbf thev shell, sets of radial links connecting the shaft and shell atspai ed intervals, each of saidsets of links being connected with said shaft through a plurality of fittings mounted to swivel independently on the shaft, the fittings for each set of links being longitudinally distributed on the shaft and having lugs extendinginto a common plane, and pivotal connectionsbe'tween said lugs and the links arranged in s aid common plane at right angles to the shaft.

ARTHUR EITROIELJ The coupling 43 occupies 

